AB1355 NAILFOLD CAPILLAROSCOPY CHANGES IN PATIENTS WITH PSORIATIC ARTHRITIS AND RHEUMATOID ARTHRITIS
Authors: E. Molteni, G. Pellegrino, C. Castellani, D. M. Reza Beigi, F. Conti, R. Scrivo, V. Riccieri
Journal: Annals of the Rheumatic Diseases (2022)

Background In psoriatic arthritis (PsA) and rheumatoid arthritis (RA) systemic inflammation is known to cause endothelial dysfunction (1) . Nailfold videocapillaroscopy (NVC) analyzes in vivo blood vessels, looking for alterations due to microvascular damage, and its application in these pathologies often highlights interesting abnormalities. PsA is characterized by lower mean capillary length and density and abnormal morphology, such as tight terminal convolutions. In RA typically elongated and dilated capillaries and prominent subpapillary plexus are described (2, 3) . Differences between RA and PsA NCV patterns are known but not well defined yet (3) . Objectives Aim of our study was to evaluate the microvascular features circulation by NVC in patients affected by PsA and RA, looking for possible differences that may characterize the two diseases. Methods We recruited outpatients affected by PsA or RA classified according to standard criteria (4, 5) referring to the Rheumatology Unit at Sapienza University of Rome. Healthy controls (HCs) without known risk factors for nailfold capillary alterations (6) were also recruited. Patients and HCs underwent NVC with a 200x magnification lens. The following morphological parameters were considered: number of capillaries per square millimeter, alterations in length, dimension, morphology and distribution of the capillary; presence of ectatic loops, hemorrhages, flux abnormalities (7, 8) . A semi-quantitative rating scale was adopted to score these changes, according to previous studies (9) . The mean score for each subject was obtained by analyzing all fingers, except the thumbs. For the statistical analysis, Chi-square and Mann-Whitney tests were used. All tests were two-sided with a significance level set at p&lt;0.05. Results We recruited 34 patients (20 with PsA and 14 with RA) and 30 HCs. For patients, the mean age was 61,7 years (SD 15,4), median disease duration was 184 months (SD 204) and males were 18 (53%). Active or past smokers were 11 (18%), 9 (15%) suffered from arterial hypertension and 2 (0.03%) from type 2 diabetes mellitus. Raynaud’s phenomenon was present in 4 patients with PsA (20%) and 6 with RA (43%). The most frequent morphological changes were tortuous capillaries (90% in PsA and 100% in RA), single-crossing shape (90% and 86%) and bizarre capillaries (30% in both groups) while multiple crossing and ramified capillaries were present in 50% and 21 % RA patients only. With respect to HCs, we found significantly more frequent changes concerning morphology, ectatic loops, presence of hemorrhages and capillary plexus visibility in both PsA and RA patients. Moreover, patients with RA showed significantly more frequent abnormalities of the blood flow with respect to HCs. These results are shown in Table 1. Table 1. Comparison of the main NVC changes in patients and HCs. NVC Changes HC PsA RA N (% ) N (% ) P value vs HCs N (% ) P value vs HCs Morphology 3 (10%) 14 (70%) p&lt;0.0001 12 (86%) p&lt;0.0001 Ectatic loops 0 (0%) 11 (55%) p&lt;0.0001 8 (57%) p&lt;0.0001 Hemorrhages 2 (0.07%) 1 (5%) p&lt;0.01 6 (43%) p&lt;0.0058 Plexus 19 (63%) 10 (50%) p&lt;0.02 7 (50%) p&lt;0.02 Flux abnormalities 3 (10%) 6 (30%) p&gt;0.05 5 (36%) p&lt;0.026 The presence of hemorrhages was significantly higher in RA rather than in PsA patients (p&lt;0.01). No significant differences were found in number, length, and distribution of capillaries between PsA/RA cases and HCs. Conclusion Our study confirms and completes the frame of NCV alterations in PsA and RA. We described for the first time alterations in the capillary morphology and the presence of hemorrhages in both groups of patients with respect to HCs. It remains to evaluate how these findings can reflect the microvascular environment of chronic arthritis. References [1]Fromm, S et al. Arthritis Res Ther 2019 [2]Lambova SN, Müller-Ladner U. Microvasc Res 2012 [3]Graceffa D, et al. Arthritis 2013 [4]Taylor W, et al. Arthritis Rheum 2006 [5]Aletaha D, et al. Ann Rheum Dis 2010 [6]Ciaffi J, et al. Microvasc Res 2020 [7]Maricq HR. Arthritis Rheum 1981 [8]Smith V, et al. Autoimmun Rev . 2020 [9]Cutolo M, et al. J Rheumatol 2000 Disclosure of Interests None declared